An open letter to America’s college cupcakes on Veterans Day

America has watched for the last year or so, as our nation’s universities have been consumed by a new strain of left wing totalitarianism that has all the traits of the haunting Marxist dictatorships of the past.

Free thought and expression and discussion are disappearing from college campuses and being replaced by behavior and lexicons out of 1984.

In the greatest arenas of free speech across this land, you shriek and howl and cry and stamp your feet like two year olds when someone disagrees with you.

You have mental meltdowns when reading passages from the world’s greatest literature that somehow offend you in every conceivable way, shape or form.

You feel oppressed and terrorized when viewing someone in a Halloween costume that you dislike.

You are triggered by opposing views from Presidential candidates, who do nothing more than say things that you may disagree with.

When triggered by every imaginable word, phrase and action on this planet, you find it necessary to retreat to so-called safe spaces, where you will be further coddled by counselors, Play Doh and Bubble Guppy videos.

Like raving martinets, you accuse anyone you disagree with of being a racist, a rapist, a sexist or any other derogatory term you can create to soothe your tender and warped psyches.

You have been told for your whole lives how special you are and these fantastical words have been reinforced by the ridiculous behavior of helicopter parents and idiotic teachers who found it necessary to control every facet of your lives and ensure that each of you precious little snowflakes received a trophy, even though many of you only deserved a kick in the behind.

Your latest irrational tirades concern the election of PRESIDENT-ELECT TRUMP. Inspired by the lunatic behavior of your socialist professors, you are the laughing stock of the rest of the country as you hold cry-ins, need therapy dogs and hide under the covers in your dorm rooms because a man was elected President.

Today is Veterans Day, when we honor those who served, which I have no doubt none of you ever have. The nation particularly honors our combat veterans who drained deep the chalice of courage and who fought against real racists, like the Nazis; real boogeymen like the Imperial Japanese Army, the Chinese, Victor Charlie, the Republican Guard and the Taliban.

Today, at this very moment, as you tearfully meltdown because Donald Trump is our next President, our current military is in harm’s way in Mosul, fighting real sexists who call themselves ISIS.

King George, Hitler, Stalin, Mao, Ho Chi Minh, Saddam, these were real threats, some of the greatest madmen the world had ever seen and our veterans fought and defeated them in hot and cold wars.

Our veterans, men and women, many of whom were your age at the time they served, never had the luxury to wallow in self-pity over imagined nonsense and monsters.

Their threats weren’t created in the hallowed ivory towers of Harvard Yard. Their threats were created in the British Parliament, in Bavarian beer halls, in jungle outposts and jettisoned across the globe to cause havoc and death. The only thing that stopped them, the only thing that prevented the world from descending into darkness was the US military and our veterans.

There were no safe spaces on Iwo Jima or Omaha Beach. There were no cry ins on Bunker Hill or at the Frozen Chosin. There were no counselors in the Ia Drang Valley or at Khe Sanh. There was no time to protest imaginary enemies at Fallujah. The enemies were real and were doing their damnedest to kill Americans and destroy our way of life.

As I stated, our enemies were fighting against Americans who were mainly your age. I and many Americans have serious doubts that you aggrieved marshmallows could rise to the occasion and fight anyone, much less the Redcoats or the Waffen SS.

How and why America has gotten to a point where being a wimp is looked upon as normal behavior for young people is the subject of another article and a disgrace in itself.

Instead of claiming half the nation is racist for voting for Donald Trump, you precious little snowflakes might want to get off your asses and read about men who overcame real prejudice and racism and fought for their country; like the Tuskegee Airmen.

Instead of being offended by words in books, you precious little cupcakes might want to step out of your safe spaces and read about American matadors at places like Trenton, the Wheatfield, Seminary Ridge, the Meuse-Argonne, the Bulge, New Guinea, 73 Easting and Tal Afar.

We have a lot of moving parts at play in the appliance repair industry today. Over the past couple of decades, appliance technology has become much more complicated, yet technician troubleshooting skills have eroded. This creates some uncertainty about the direction our industry is going.

Are we going to be a profession, filled with well-paid, highly-skilled technicians at the top of their game, or a semi-skilled trade, filled with low-paid parts changers who are essentially just the eyes and hands carrying out the directions of tech-line personnel? Will both of these types of techs coexist, or will one go extinct?

We’ve worked with thousands of techs and scores of business owners online over the years, most of whom take training and their profession seriously. We meet lots of folks like that at events such as ASTI. It makes us feel that the transition from trade to profession is here, and here to stay.

A big wake-up call for the Samurai

Recently, however, I had an abrupt reminder that there are still many who are not on board with that vision and are also influencing the direction of our industry.

I was doing ride-alongs with techs at a large service company to assess the effectiveness of our online training at The Master Samurai Tech Academy. I was surprised and dismayed to see that the techs weren’t using many of the techniques that we emphasize in our training, such as coming to a job prepared with tech documents, doing a simple load analysis using the schematic, and performing electrical measurements from easy-access locations to definitively identify the component failure. In fact, they seemed to have forgotten even how to do many of these things.

What the heck? Where did I go wrong?

It all became clear to me when I had a chance to go over the day’s calls with a service manager for the company. When I described the troubleshooting methods we used on a dryer call, he declared that we had gone "full retard" (a phrase from the movie Tropic Thunder) for actually looking at the schematic, doing a few amp readings and one simple Ohm’s Law calculation.

I was speechless. This is the guy who is supervising the techs who were paid to go through Master Samurai Tech training. However, it explained what I had seen that day. Although one of the senior managers at this company saw the value of using the MST Academy training for their techs, the other managers were not on board. Many of the skills taught at the Academy were not just ignored or discouraged, they were outright ridiculed. So of course the techs basically became parts-changers who simply carried out instructions from their manager or tech line.

At that point, another movie came to mind, Idiocracy, which imagines the dismal result of several hundred years of cultural anti-intellectualism.

I’m used to encountering techs who are a bit defensive about their lack of troubleshooting skills, but when even service managers mistake pattern recognition, parts changing, and a collection of factoids for real troubleshooting or, worse yet, have become hostile to it, then idiocracy is gaining a foothold in the appliance repair trade.

Attitudes: the good, the bad, and the ugly

Over the past decades, the technical skill level among many appliance techs has degenerated to such a low level that they don't even know what cause-and-effect troubleshooting is anymore. Since service managers are now being promoted from this group of techs, this attitude has become firmly entrenched in some organizations.

In all my dealings with techs over the past 20 years, I have come to realize how phenomenally important attitude is. And I’ve seen it all. Some techs love to keep learning and sharpening their skills, no matter how many years they’ve been doing it, and enjoy the pride of accomplishment and the profits that come along with it. Then there are others who have worked long enough to have some know-how based purely on pattern recognition (“if this problem on that model change this part”) and resist the notion that their job performance and income would benefit even further if they learned real troubleshooting skills. The causes of this attitude include ignorance, arrogance, and laziness. Ignorance is curable through outreach and training. Arrogance and laziness are difficult and dangerous qualities in a tech, but even worse in someone who is in a leadership role.

What's the risk to the industry if too many techs go down the road of idiocracy? Doesn’t that just give an opening for more success by those companies that behave like professionals?

Not necessarily. The expression "a rising tide lifts all boats" works in the opposite direction as well. The experiences our customers have with “parts changers” can negatively impact their future interactions with other service companies. They will often be more suspicious and price sensitive.

Furthermore, appliance manufacturers are seeing this problem in the appliance repair industry today, too. They realize there is uneven, often inadequate technical expertise in the trade. As a result, they are adapting to this general dumbing down in troubleshooting skills by dumbing down their training programs to essentially spoonfeeding what's already in the service manuals, knowing that most techs don't RTFM. They're also developing new technologies to decrease reliance on field techs to troubleshoot and solve problems.

Here's what the future could hold:
- Wifi-enabled appliances will report errors and diagnostics directly to the manufacturer's central technical staff who are specialists in that product.
- Corporate techs can then run diagnostics and do most troubleshooting remotely.
- The service company is then dispatched to simply replace a part- no troubleshooting required.

If this comes to fruition, the end result will be a decrease in skill level expectation from technicians. And since higher pay accompanies and incentivizes the acquisition of specialized skills, there will be a concomitant reduction in "technician" pay and skill level. Service managers will be be reduced to route makers and time card checkers with a corresponding reduction in their skill level expectation and pay.

All is not lost on this front. I speak with enough manufacturers to know that they would still like a better trained corps of appliance techs out there who can keep our mutual customers more satisfied. They haven’t given up on us yet!

Take a look at yourself! Have you looked at yourself?

I’m sure most of you reading this don’t come anywhere near being the kind of person who would call technical troubleshooting going "full retard." But, we would all benefit by stepping back and taking an honest look at our attitudes and expectations to see what part we are playing in raising our trade to a profession, and identify (and remedy) any weak links in our organizations.

After all, if you’ve invested in training the techs in your company, it’s a waste of money if you aren’t implementing and nurturing the skills and practices that the techs learned in that training.

Here’s what I still see too often when I go on ride-alongs with techs. Do you recognize any of these traits in your own service calls?

1. The tech arrives at the service call with no technical literature (service manual, tech sheet, bulletins) pre-loaded on his tablet or notebook computer. A manager may have pre-screened the calls and had probable parts pre-loaded on the service tech's vehicle, but the tech himself/herself is walking into the call completely cold.

2. If the call is anything other than a simple mechanical problem or parts replacement, the tech calls either his service manager or the manufacturer tech line.

3. Either way, the tech is spoon fed information to complete the diagnosis or repair; he is merely following detailed instructions but not doing the troubleshooting himself. From the tech's standpoint, this is only adding to his internal database of pattern recognition and factoids.

4. Neither the service manager nor the tech line guy has the time, patience, or skill to use this experience as a teaching moment and coach the tech through a troubleshooting thought process by asking leading questions. Examples:
- what is your load of interest on the schematic?
- what other components have you identified in the circuit for that load?
- where does the schematic indicate that you would test the power supply for that load?

5. The appliance may get repaired as a result of the spoon feeding but the tech never grows in his ability to perform independent troubleshooting analysis-- he has simply added another pattern to his repertoire for recall on another job with the same problem. Reliance on outside counsel such as service manager and manufacturer tech line, which should be a rare event for a skilled tech, is perpetuated. Job security for the service manager and tech line guy is assured, but no skill growth for the service tech takes place.

The foregoing is a typical pattern of degraded tech performance that is accepted as the "new normal" by far too many service companies. The problem is compounded when the service company middle management-- the service managers-- not only accept this degraded performance, but defend it.

Pattern recognition and a head full of factoids do have their place in appliance repair. In fact, these form the basis of experience in older technicians, allowing for quick diagnosis and repair of commonly-occurring problems with known solutions. But these experiential skills should not be mistaken as classical troubleshooting and are insufficient for service calls with problems that don't fit the pattern or are "off the flow chart."

The rewards of professionalism

Techs who take the time to hone their craft with training, continuing education, and pre-diagnostic work are true professionals. Being prepared and able to competently troubleshoot any type of appliance and failure scenario is where the big payoffs happen in terms of reputation and profit. First Call Completes are maximized, callbacks are minimized, and cheerleader customers are forged. That’s what a professional business looks like.

Is it too late to turn back the tide of idiocracy in the appliance repair trade? We at Master Samurai Tech firmly believe it is not too late and we have developed affordable, time-flexible training solutions to aid our brethren in the Craft. These skills are eminently learnable by anyone who desires to do so, and we’ve seen countless examples of techs and owners who have reaped the rewards of rising to the challenge.

Join us, and help avert the future portrayed here:

In a recent webinar, I offered a mental framework for executing classical troubleshooting strategies during service calls. Professional Appliantologist members and Master Samurai Tech Academy students may watch the 1-hour webinar recording here:

Great turn out for this webinar-- had over 30 people on! That means there are lots of techs who recognize the need for help with these skills. This is good because they can be easily learned by anyone who wants to learn them! This webinar lays out a road map for you to declare your independence from tech lines.

Good morning, ladies and gentlemen, this is your Samurai speaking. We're expecting a little turbulence today as we make some adjustments to the Master Samurai Tech Academy website. There may be periods throughout the day where the site either doesn't load at all or may look strange. This, too, shall pass.

For now, I invite you to sit back, relax, and peruse the latest pearls of appliantological wisdom in my blog here at Appliantology.

Samsung's in the news lately with exploding washers and tablet computers. So people may be wondering how reliable Samsung appliances are. Here's a good article from the Yale Appliance blog comparing Samsung repair rates with industry averages. Yale Appliance and Lighting [website] is a large appliance dealer and service center in the Boston area. Yale completes over 20,000 service calls per year so I expect their results to be a good representation of reality.

One comment that caught my eye, "Also, many technicians cannot fix the Korean brands for whatever reason. You may want to check that your dealer can service before you buy Samsung or LG."

You may be asking yourself why this is the case. This illustrates a huge problem in the appliance repair trade today: there is a critical shortage of skilled technicians who understand appliance technology (basic electricity and electronics, motors and motor control systems, microprocessor-based control systems, etc.) and know how to troubleshoot. As a result, many appliance servicers are really parts changers who do "troubleshooting" by pattern recognition: if this problem, replace that part. So if something merely looks different than what they're used to seeing, they're at a complete loss.

The reality is that electricity works the same way in Korea as it does everywhere else on Planet Earth and the Koreans are using the same technology as all the other manufacturers. But because the Koreans give more details in their service information (for example, showing circuit details of their control boards) parts changers freak out and think they're using space-age technology.

Are Samsung Appliances Reliable? (Reviews)

I was watching the news last week and learning about Samsung's problems with phones exploding for no clear reason. Most new products have issues in my experience. The computer industry innocently calls them bugs.

Exploding products is a problem especially when you deliver them in your home. Gas ranges, dishwashers, and laundry can cause more damage than a phone.

So I wanted to answer the question: Are Samsung appliances reliable?

Measure of Reliability

Every year our service department completes over 20,000 service calls. Our formula is service calls divided by sales as a percentage of service within the first year. Then we compare brands and products as we have in various articles for a 12 month period.

We will compare Samsung's service rates to the industry in their major categories: Cooking (not including microwaves, because they do not break in any brand), laundry, dishwashers and French door refrigerators.

BTW, these numbers always change as they are measured on a 12-month rolling basis. Also, we have only sold Samsung for 18 months, so I do not know about the products manufactured before 2014.

Samsung Reliability Numbers October 2015-October 2016

Laundry

Front Load Washers: 13 Serviced / 130 sold - 10%

Top Load Washers: 0 Serviced / 35 sold - 0%

Dryers: 10 Serviced / 92 sold - 10.4%

Industry average is just over 11%, so Samsung is slightly better. There have been 21 cases of the top load breaking apart due to the rod unfastening. However, 21 out of millions sold since 2011 throughout the country seems relatively small. However, this could be a concern.

Should You Buy a Samsung Appliance?

People ask me about what to buy all the time on this blog. I always say the same thing. I like what does not break because we have to fix broken appliances.

But I will answer the question on Samsung more directly.

The product seems reliable as the numbers show.

When there are problems, their logistics of parts and technical support are not as easy as a Frigidaire or Bosch. Also, many technicians cannot fix the Korean brands for whatever reason. You may want to check that your dealer can service before you buy Samsung or LG.

However, the product seems to be designed incredibly well. The new induction with the blue LED “flame” is creative, as are the designs of the French doors and front load laundry.

A company who has battled Apple successfully over the years (until recently) cannot be underestimated especially in a staid industry like appliances.

Additional Resources

Looking for answers before you buy major appliances? Get the Yale Appliance Buying Guide with detailed profiles of the major brands plus answers to the 10 most asked questions. Well over 185,000 people have read a Yale Guide.

I had the pleasure of attending Sub-Zero Wolf (SZW) factory training last week in Madison, WI. Flew in on Monday, training was Tuesday thru Thursday, and then flew out on Friday. The class consisted of 15 techs from around the country but also included a tech from Puerto Rico and another from Barbados. The techs included a few students from Master Samurai Tech and some Appliantology members.

This session was all Wolf products: gas and induction cooktops, gas and dual fuel ranges, vent hoods, downdraft vents, coffee makers, and microwaves. We worked on 5 different wall ovens, 4 different ventilation systems (both hood and down draft), 4 different ranges, 4 different cooktops, 2 different microwave ovens, a steam oven (each lab group actually baked a batch of chocolate chip cookies!), and the coffee maker system.

The 3-day training session was held in Madison, WI, from October 11-13 (Tuesday thru Thursday). Everyone arrived on Monday and SZW took us all out that evening for a traditional Wisconsin dinner of locally brewed beer and real Wisconsin brats and sauerkraut, beef brisket, and mac n' cheese. It was fantastic! SZW provided all our food during the training and paid for our hotel rooms. Breakfast was at the hotel, lunch was catered at the training center, and they took us out to a different restaurant each night for dinner. A shuttle took us from the hotel to the training center and back each day.

The training format was a mix of classroom instruction and "lab" exercises. During the lab portion, we broke up into groups of 3 or 4 techs and rotated around working on different product stations as we solved specific problems on those products. Doing this required extensive use of Sub-Zero's servicer site, Service Central, that we accessed on our tablet computers to find and refer to service manuals, schematics, and bulletins for the model/serial we were working on. Numerous rolling tool chests and Fluke meters with the LoZ function were also provided. Instructors would roam around from group to group to answer questions and provide hints, tips, and instructions. This was a great format for getting familiar with the products.

Part of the training was a factory tour of the Wolf production facility including the new 4,000 sq. ft. manufacturing space to accommodate the production of their new dishwasher, Cove, which they'll start selling in 2017. The facility was immaculate, highly organized, with surprisingly few production personnel on the floor. What amazed me most about the manufacturing process was the amount and sophistication of robotics they're using for everything from fabrication to QC testing. Every finished product is connected to electricity and/or gas (as appropriate for the product) and 100% function tested using robots!

After the factory tour, we got to sit in with a tech line tech and were given a headset so we could listen in to both sides of the conversation as they took calls from techs in the field. It was dizzying seeing how fast these guys could fly around Service Central pulling up service manuals and bulletins to help the tech on the phone. Most of the guys who called in while I was there were authorized and had access to Service Central so could have probably answered the question for themselves if they had just spent a few minutes at Service Central and then RTFM. Getting authorized techs to effectively use Service Central is one of SZW's big training objectives. Even among SZW authorized techs, there's an over-reliance on tech line and flow charts instead of reading the service manuals, using the schematics, and applying gray matter.

By the way, SZW tech line will help any tech, authorized or not, who calls in working on one of their products. Non-authorized techs are treated exactly the same as authorized techs and they'll be talked through as much as they need to complete the diagnosis and repair, including step-by-step disassembly if needed. Their main concern is getting the customer's appliance fixed as quickly as possible, not protecting SZW service information.

Sitting with tech line, I also realized why SZW uses a select circle of parts distributors (Premier Partners). Here's a typical scenario: a tech calls in working on a SZW product and, working with tech line, determines he needs a kit described in a recent service bulletin to fix the problem. Tech line is tied directly into the inventory database of all their Premier Partners and can tell the tech if that kit is in stock there or not. If it is, he'll go ahead and have that part shipped right then and there. If not, he can check factory inventory and have it shipped to the partner right there during the call. There's no ambiguity about whether a part is in stock or where it is or when it will arrive like there is with so many other manufacturers.

In addition to a great technical training experience on Wolf products, I also got a good feel for the SZW corporate culture. Not surprisingly, it reflects the people who work there, mostly native midwesterners and particularly Wisconsin: not at all stuffy or pretentious but instead clean, organized, competent, down-to-earth, get things done. Real people making really excellent, 100% US-made appliances. If any of you guys are SZW authorized and haven't been to the factory training yet, you really should go. I think you'll be impressed and learn one helluva lot.

In this video, I use an old skool Whirlpool electric dryer to demonstrate electric circuit troubleshooting and analysis techniques. This is the ancient art of Circuit Fu. Although this is a simple circuit by today's standards, the principles and techniques can be used on any circuit because electricity works the same way. When you know basic electricity and circuits, you can decipher these diagrams and become a troubleshooting master...

Learn Circuit Fu and how to kick appliance butt at the Master Samurai Tech Academy. The training is distilled down to the fundamental essentials that every appliance tech should know (but, alas, many do not). The training covers the classic skills, like those shown above, yet is up to to date with the current technologies used in modern appliances. Our training is affordable for anyone, self paced, on demand, and comprehensive.

During the webinar, Joe asked how triacs are turned off. I wanted to give a more complete and accurate answer in this post.

To understand how triacs are turned off once they're turned on (and conducting) we need to have a little understanding about how triacs work. So that's what I'm going to do here. Before we light this candle, I'll start with the three take-away points that we need to know about triacs:

1. Triacs are used to control AC power supplies

2. You can think of them as solid state relays

3. Triacs are current controlled devices. This means that you need electrons bustin' down the Gate to turn it on AND you need load current flowing through them in order to stay on.

Okay, here we go...

Intro

The word "Triac" is an acronym that stands for Triode for Alternating Current. "Triode" is the old Skool word for a three-terminal (or electrode) vacuum tube used to amplify a signal.

Triacs are used to control a AC power supply. In appliances, they are used to turn the AC power supply off or on.

Here's what a typical triac looks like, such as what you might find on an appliance control board:

Here is the schematic symbol:

The leads labelled A1 and A2 stand for “Anode 1” and “Anode 2.” You will also see them referred to as “MT1” and “MT2” where MT stands for Main Terminal. Same thing. This is the business end of the triac where the main working current passes. This part of triac can complete the circuit for lots of different AC loads, from light bulbs to motors.

The other important thing to point out is the “G” terminal. This is the Gate and it has the power to turn the triac on with just a little DC voltage, usually a 5 VDC digital pulse generated by a microprocessor. So this little Gate voltage and tiny current can make a triac turn on and pass a heap big mondo working current.

Triacs are like solid state relays and, in the appliance world anyway, serve the purpose of the relays with a coil and set of contacts. The difference is that triacs don't have metal contacts that can arc and burn out and don't have a coil. (And, of course, triacs are made of semiconductors and PN junctions. More on that in a bit.)

Relays are electromechanical devices whereas triacs are solid state devices.

Inside a Triac

Triacs have two sets of three PN junctions. Look at the diagram below:

As with any semiconductor device, it requires current flowing through it, or more properly stated, electrons being forced through it by a voltage source, in order to collapse the PN junctions and cause it to start conducting. Refer to the webinar recording on “Semiconductors and PN Junctions” in the Professional Appliantologists forum and at Master Samurai Tech for more details on this.

The triac is constructed in such a way that a little tiny gate current is all that's needed to “forward bias” the triac and make it turn on and conduct a large AC current that can drive a load like a motor. This Gate current is typically driven by a small DC voltage like 5VDC.

Turning a Triac On and Off

Triacs require a minimum current through the Gate in order to turn on. In order to stay on, they also need a minimum load current flowing through them from MT1 to MT2. This is called the “holding current.” This is why we say that triacs are current controlled devices.

When the AC voltage crosses the zero line (the x-axis), the current then goes to zero and the triac “turns off.” So the triac naturally turns off at every half cycle of the AC sine wave. The Gate voltage, which produces the Gate current, must then be reapplied in order to the turn the triac on for the next half cycle.

Let's look at this:

In the diagram above, the sine wave is the current passing through the triac from MT1 to MT2 (or A1 to A2, same thing). The notches represent the triggering points where Gate current has to be supplied in order to keep the triac turned on for the next half cycle. Also notice the holding current dashed lines. This is the minimum current that needs to be passing through the triac in order to stay on.

AC voltage goes to zero every half cycle (120 times a second in a 60 Hz power supply). No voltage means there's no current because current, electrons, cannot move unless there is a voltage difference between two points as you learned in the Basic Electricity module of the Fundamentals course.

Since there is no current flowing through the triac at this point forcing the PN junctions to stay collapsed (current drops below the minimum holding current required to keep the triac conducting), the triac turns off and stops conducting.

To get the triac to turn on and start conducting again, you have apply a Gate trigger voltage (which drives the gate current) to the Gate terminal. If you to want to have the triac conduct through several AC cycles, you have to re-apply the Gate trigger voltage each and every time the AC voltage sine wave goes to zero (i.e., when it crosses the x-axis).

Here's another diagram showing the gate current triggering pulses:

A couple things to notice about the graph above:

1. Look at the timing of the Gate current pulse. It occurs right around the time the AC load current through the triac goes to zero.

2. You don't need to keep supplying Gate current the entire cycle to keep the triac turned on, just when the load current goes to zero. So you can supply Gate current in specifically-timed pulses. We're talking accurate timing down to the microsecond. Mind boggling for us; piece of cake for a microprocessor-- they do this kind of stuff all day long.

If you were to connect an oscilloscope to both the gate voltage and the voltage output at one of the the triac main terminals, it would look something like this:

The Gate pulses in the oscilloscope photo above are wider than the ones in the preceding diagram but the idea is exactly the same. Channel 1 is the Gate voltage and Channel 2 is the AC voltage output of the triac.

I'm talking about voltage now. That's perfectly fine because in non-reactive devices, like triacs, there is no phase shift between current and voltage. So whatever voltage does, current also does at the exact same time. It's just easier to show voltage on an oscilloscope.

Notice that the gate pulse on Channel 1 goes from zero to 5.5 VDC each and every time the AC voltage sine wave on Channel 2 crosses the x-axis (at which point the AC voltage is zero). So while the frequency of the AC line voltage is 60 Hz, the frequency of the Gate pulses is 120 Hz. You can see this in the lower right hand corner of the photo above.

Since the AC voltage (and hence current) goes to zero 120 times a second, all you need to do to stop the triac from conducting is remove the Gate voltage. Done!

The Two Golden Rules for Gating Triacs

1. To turn a triac ON, a gate current greater than the minimum required for that particular triac model must be applied until the load current is passing through from MT1 to MT2 . Being a semiconductor, temperature affects this and is one of the design considerations the engineers have to consider.

2. To turn off a triac, the load current must go below the minimum holding current for that particular triac model long enough for the PN junctions to re-establish themselves. We're talking microseconds here. And, of course, remove the Gate current. With the Gate current removed when the load current (and hence voltage) goes to zero, the triac will not conduct, even if the load voltage later goes to something other than zero.

Summary

1. Triacs are used to control AC power supplies

2. You can think of them as solid state relays

3. Triacs are current controlled devices. This means that you need electrons bustin' down the Gate to turn it on AND you need load current flowing through them in order to stay on.

No schematics on this one! I know that'll be a relief for some of you. Honestly, it was a nice break for me, too. I love these easy jobs where you can troubleshoot using only your eyeballs and fix it with something as simple as a paper clip.

In this short little video, I show you how to troubleshoot a problem with a surface burner on Bosch gas range. The burner was not lighting correctly and would sometimes flare up.

All gas range surface burners operate using the same principles so don't let the fact that this is a Bosch fool you. Gas fuel, just like electricity, works the same way in the US as it does in Germany, Korea, or anywhere else in the world. So the same principles and repair shown here apply to all gas surface burners regardless of brand.

In case you missed it or would like to review, Professional Appliantologist members here at Appliantology may watch the recording on Linear Motors and Linear Compressors webinar on August 15, 2016 here:

And just a reminder that Professional Appliantologist members have convenient access to all the webinar recordings on the Webinar Recordings Index page here:

This short little video shows you how to enter program mode in Bosch SHE SHU model dishwashers. You'll want to enter program mode to retrieve error codes, which can help inform your troubleshooting strategy. You can also run the test program, which is helpful in diagnosing individual loads in the dishwasher.

One of the many benefits of Professional Appliantologist membership at Appliantology is hi-speed, unlimited service manuals and tech sheet downloads at Appliantology.org. Included with your membership is access to exclusive webinars and webinar recordings where you get deep, specialized training in appliance technology and troubleshooting strategy with the Samurai.

Professional Appliantologist members should also watch the video where I who to troubleshoot a no-heat problem using live tests:

In this video for Professional Appliantologist members and Master Samurai Tech Academy students, I show you how to troubleshoot a Bosch dishwasher no-heat problem. No heat problems can manifest in a variety of ways: really long cycle times, a "1" shown on the display at the end of the cycle, or as an error code. Some models will show an error code readout, others may just show the error code as a flashing light. Whichever way, you need to troubleshoot the heating circuit.

As with all electrical problems, you need to use the schematic to pinpoint the open (bad) component. The problem could be the circuit board heating relay, the heater thermostat, the heating element itself, or the pressure switch. I show you how to use the schematic and live voltage tests to pinpoint the exact problem.

Join the Samurai on this Samsung electric dryer service call and learn how to troubleshoot a no-heat complaint from the control board, without having to tear apart the whole dryer, by using the schematic and strategic electrical tests. Work smarter, not harder!

Professional Appliantologist members here at Appliantology should watch my webinar recording on troubleshooting this same problem using live voltage tests for deeper understanding of troubleshooting techniques

Most appliances today use computers to control the various appliance functions. Computers talk in logical 1's and 0's which are actually pulses or square waves of voltage that you can see on an oscilloscope or measure with a meter. These pulses are arranged in a specific sequence to transmit and receive information inside the appliance. In this video, the Samurai uses a Samsung dryer to show you what these pulses look like and how to use this information for troubleshooting.

This LG refrigerator was DOA- warm inside, no compressor operation, no lights, no nuttin'. Found a blown fuse on the main control board. What took out the fuse: bad board or just a spike on the power line? I show how to check for that.

The fuses on these LG boards are soldered in and not easily replaceable. But a new fuse can be installed and I show how to do that without even having to remove the board, while it's still installed in the refrigerator.

This short little screencast by @Son of Samurai shows you how to renew your Professional Appliantologist membership at Appliantology.org so you can continue to enjoy the many benefits the site provides to professional appliance repair technicians.

Introducing the mysterious Son of Samurai (yes, the actual spawn of Samurai), the man behind the scenes running Appliantology.org and MasterSamuraiTech.com. He's also a certified Master Samurai Tech and the Samurai's service call partner. In this episode we talked about:

- Son of Samurai, who he is and what he does to keep our websites running
- Behind the scenes at Appliantology
- Common user questions at Appliantology
- What it takes to be a professional appliance repair technician today
- Getting the most out of your Professional Appliantologist membership at Appliantology.org

If you're contemplating doing work for someone who lives out of town (eg., rental property in your area) and whom you've never met, it's worth spending a few minutes looking them up online. Google is your friend! Choosing the wrong customer can cost you a bad online review, even though you've already refunded 100% of their money after you've provided services. There are people out there (mostly real estate types) who take a sadistic pleasure in screwing over service companies. Here's an example of such a guy: http://toddhwaller.com

This is an excerpt of the full split-phase household power supply webinar held on June 6, 2016. In this excerpt, I explain why antiphase sine waves (meaning 180 degrees out of phase with each other) cancel each other out in a sound mixer but not in a center tapped transformer. Just because an AC voltage can be represented or modeled as a sine wave does not mean all sine waves behave the same way everywhere regardless of the device-- you have to know what you're measuring!

Household power supplies in North America use what's called a split-phase system. The transformer on the pole outside the house takes grid power and steps it down to 240 VAC from end to end on the secondary winding. The secondary winding has a center-tap in it which splits this 240 VAC into two 120 VAC voltages from either end to the center tap. This center tap is defined as Neutral and it is tied to Ground in the circuit breaker box inside the home. The two 120 VAC voltages are 180 degrees out of phase with each other and it is this very antiphase relationship that creates the voltage difference of 240 vac between L1 and L2.

There's a lot of disinformation and tech myths out there about 120/240 split-phase household power supplies. You may have even seen videos online claiming that the split phases are in-phase with each other. This is complete hogwash and I prove it to you in this video.

I show the proper phase relationship (180 degrees) between Line 1 to Neutral and Line 2 to Neutral right at the circuit breaker box using an oscilloscope.

I challenge anyone to show differently and to clearly show how you're measuring.

First, had a very interesting conversation with Brother smee about carbon monoxide, measurements, standards, production and health effects. We pulled up this excellent training presentation from GE, that demystified a lot of the confusion about CO, and looked at it together:

Might make a good topic for a future Office Hours.

Next, had a good conversation with Mr.Pro-- to be continued-- as we tracked down a DE1 error code on a Samsung washer he was working on. We thought we were looking at the same Fast Track but turns out not to be the case. The correct Fast Track for his model is this one:

Probably shoulda taken that one to a Join.me webinar to make sure we were on the same page. Anyway, we at least established that much! We'll nail the rest of it down in a later chat.